The company added it was halting the operation of a gas turbine due to the "technical condition of the engine", blaming Germany's Siemens Energy for failing to return on time gas-pumping units that it had taken for repairs.
Daily capacity via the Portovaya compressor station will fall to 67 million m3/day from 00:30 CET on June 16.
The gas turbine that powers a compressor station on the Nord Stream 1 pipeline had been in service for more than 10 years and was taken to Canada for a scheduled overhaul.
The delay in returning the equipment to Gazprom was because they were taken to Canada for a scheduled overhaul and have not been returned due to Ottawa's sanctions on Russia.Siemens Energy has withdrawn its services and maintenance support for Russia in order to comply with Western sanctions.
Gazprom also cut gas exports to Italy, Italian energy firm Eni said on June 15, adding no explanation had been given for the reduction.
Italy is the 2nd-largest European buyer of Russian gas after Germany.
Benchmark European gas prices have again surged.
The front month on the Dutch TTF was last seen trading above EUR 108/MWh, up almost 12% day on day.
The EU seeks to diversify away from Russian energy.
On June 15 EU Commission President Ursula von der Leyen signed a deal with Egyptian President to pipe gas to Israel, where it would be liquefied and delivered via ship to the EU.